A nurse assesses a client who is prescribed a medication that stimulates beta1 receptors. Which assessment finding would indicate that the medication is effective?

Correct Answer: A

Rationale: The correct answer is A: Heart rate of 92 beats/min. Activation of beta1 receptors increases heart rate. Therefore, a heart rate of 92 beats/min indicates that the medication is effectively stimulating beta1 receptors. Choices B, C, and D are incorrect as they do not directly correlate with beta1 receptor stimulation. Choice B (Respiratory rate of 18 breaths/min) is influenced more by beta2 receptors. Choice C (Oxygenation saturation of 92%) is related to oxygen levels in the blood, not beta1 receptor stimulation. Choice D (Blood pressure of 144/69 mm Hg) is more affected by alpha receptor stimulation than beta1 receptor stimulation.

Correct Answer: D

Rationale: The correct answer is D. Epinephrine causes vasoconstriction, which can lead to vascular ischemia in digits. In delicate surgeries like finger reattachment, maintaining adequate blood flow is crucial for successful outcomes. Using epinephrine can constrict blood vessels excessively, leading to reduced blood supply and potential tissue damage. This can result in vascular ischemia, compromising the viability of the reattached finger. Explanation for incorrect choices: A: Epinephrine actually helps in reducing blood loss by constricting blood vessels. B: Epinephrine reduces tissue swelling, making surgery easier. C: Epinephrine is not contraindicated in emergency surgery; it is often used to control bleeding and prolong anesthesia.

Correct Answer: C

Rationale: The correct answer is C: Organic phosphate. Pralidoxime is used to treat toxicity caused by organophosphates, which inhibit cholinesterase enzymes. Pralidoxime works by reactivating the inhibited cholinesterase enzymes, restoring their function. Atropine is used to counteract the effects of excessive acetylcholine in cholinergic toxicity, not organophosphate poisoning. Nicotine is a nicotinic receptor agonist and not treated with pralidoxime. Amphetamine is a central nervous system stimulant and does not involve cholinesterase inhibition. Therefore, the correct answer is C as pralidoxime is specifically used to treat toxicity caused by organophosphates.

Correct Answer: B

Rationale: The correct answer is B: Prazosin. α-1 adrenergic receptors are selectively blocked by prazosin. Prazosin is a selective α-1 adrenergic receptor antagonist, specifically targeting these receptors. It works by blocking the effects of norepinephrine, leading to vasodilation and reduced blood pressure. A: Phentolamine is a non-selective α-adrenergic receptor antagonist, blocking both α-1 and α-2 receptors. C: Propranolol is a non-selective β-adrenergic receptor antagonist, blocking β-1 and β-2 receptors. D: Ergotamine is a medication used for the treatment of migraines and has vasoconstrictive properties but does not selectively block α-1 adrenergic receptors.

Correct Answer: D

Rationale: The correct answer is D because physostigmine is used in the treatment of glaucoma due to its ability to lower intraocular pressure. It works by inhibiting the enzyme acetylcholinesterase, leading to increased levels of acetylcholine which helps in constricting the pupil and improving drainage of fluid in the eye. Options A and C are incorrect as physostigmine is a tertiary amine and a reversible anti-cholinesterase. Option B is incorrect as physostigmine does have CNS action, crossing the blood-brain barrier and affecting brain function.